In vehicles of recent years, a control device that assists the driving operation at the time of the travelling of the vehicle is being developed to enhance the easiness in driving at the time of the travelling of the vehicle, to reduce the load of the driving operation by a driver, and to enhance the safety at the time of the travelling of the vehicle.
For example, in a rear-end collision preventing device described in patent literature 1, it is provided to enable wireless communication between vehicles, where a leading vehicle transmits, by wireless communication, a status where sudden braking is anticipated, and an own vehicle that received information from the leading vehicle maintains a brake system in a brake activation waiting state. Thus, when a driver of the own vehicle performs a braking operation, the own vehicle immediately starts to brake, and thus the own vehicle can be prevented from making a rear-end collision with the leading vehicle even if the leading vehicle makes a sudden braking.